P-165: Chronological age as a prognostic factor in transplant-ineligible patients with newly diagnosed Multiple Myeloma

Abstract

<h3>Background</h3> Myeloma Multiple (MM) is a hematological malignancy that affects elderly patients mainly. Due to the heterogeneity of this population, a geriatric evaluation is recommended to decide first-line therapy. However, its application is laborious, and its use in clinical practice is not widespread, being therapeutic decisions usually made according to chronological age. The aim of this study is to evaluate the clinical characteristics and evolution of a series of 148 newly diagnosed transplant-ineligible MM patients according to different age group. <h3>Methods</h3> Retrospective study of patients with newly diagnosed MM, diagnosed in two tertiary hospitals in Spain, between 2015-2020. According to age at diagnosis, patients were grouped in ≤79 (Group 1; n=90) and ≥80 (Group 2; n=58) years. The International Myeloma Working Group criteria were used to evaluate treatment response. <h3>Results</h3> The median (range) age of patients in Group 1 and 2 was 74 (70-79) and 83 (80-92) years, respectively. There were more patients with ECOG >2 (5.6 vs 17.2%; p=0.01) and ISS 3 (38.9 vs 53.4%; p=0.013) in Group 2. Remaining characteristics at diagnosis were similar in both groups. The most frequently administered treatments were bortezomib-based (43 patients in Group 1 and 22 in Group 2), followed by regimens with lenalidomide (18 patients in Group 1 and 20 in Group 2). Overall, 66 (73.3%) patients in Group 1 and 40 (71.4%) in Group 2 achieved partial response or better after treatment. The rate of very good partial response or better was 53.3% and 50% in Groups 1 and 2, respectively. Finally, 24 (26.6%) patients achieved complete response in Group 1 and 9 (16.1%) in Group 2 (p = 0.1). Nine (37.5%) out of 24 patients in Group 1 and 3 (33.3%) out of 9 patients in Group 2 achieved minimal residual disease negativity by flow cytometry, with a sensitivity of 10-5. With a median follow-up of 23.5 months, the progression-free survival (95%CI) of Group 1 and 2 was 33.13 (25.9-40.4) and 26.43 (16.6-36.2) months, respectively (p = 0.680). Median overall survival was 50.4 (33.4-67.4) months in ≤79 years and 28.1 (22.5-33.6) months in ≥80 years (p = 0.014). Overall, 38 patients from Group 1 and 33 from Group 2 have died, being infections the leading cause of death in both groups. It should be noted that 22 patients (24%) of Group 1 and 24 (41%) of Group 2 did not reach second line of therapy. <h3>Conclusions</h3> Patients aged ≥80 years often have a worse general condition at diagnosis, but the rest of the baseline clinical characteristics are similar to those of patients aged ≤79. There were no differences in terms of the rate and quality of responses between both groups of patients. There was a high attrition rate, particularly among patients ≥80 years, highlighting the need to design specific therapeutic strategies for this fragile group of patients.